That means warmer poles which would cause polar ice to sublime into gas, thickening Mars' atmosphere so the water could fall as snow at lower, latitudes. This idea was put forth earlier this decade by James Head III of Brown University, who five years ago presented numerous features in this same region that looked suspiciously like glaciated terrain on Earth.
"Essentially all of the features were known from the Viking spacecraft in the late 1970s," said veteran Mars scientist Vic Baker of the University of Arizona. Head's work made the case yet again using much higher resolution images, he said.
"Mars was screaming at us that it had a lot of water and ice," said Baker, speaking metaphorically. The problem was the evidence was all based on the science of geomorphology, or land forms, which is not an area a lot of physicists put much stock in, said Baker.
Now that a radar instrument is backing up the geomorphology that's been known for decades, "A lot of physicists will start working on it," Baker said. Which is a good thing, he added.